华法令抗凝观察指标是（） A.APTT在正常值的2～3倍间 B.APTT在2～3秒

     Last month, Tom spent his holidays in a small town. He stayed at a small hotel    1     the train
station for many days.
     One night, before he     2   , he went to the owner of the hotel and asked, " Will you please wake
me up at    3     tomorrow morning? I have to catch the five o'clock train." "Oh, sorry," the owner said,
"I     4    get up so early." Then Tom asked the owner, "Have you got     5    alarm clock?     6    it can
help me." "Yes, here you are, Sir." The owner said. Tom thanked him and     7    his room. However,
when he     8    the clock carefully, he found there was     9    with it. Tom left his room and
asked the owner again.
     "Excuse me, are you sure the clock will ring on time?" Tom asked. 
     "   10    ,  Sir!" said the owner, "When you shake it at 4:45 in the morning, it will ring."